On Saturday, Luis's parents gave birth to twins and named them Umaima and Ishaan. When they were first born, Umaima weighed 7.63 pounds, and Ishaan weighed 8.4 pounds and was 20.5 inches tall. How much did the babies weigh in total?
Solution: To find the weights of the 2 babies, we need to add their weights together. Umaima's weight + Ishaan's weight = total weight. ${7}$ ${6}$ ${3}$ ${8}$ ${4}$ ${0}$ ${+\vphantom{0}}$ ${3}$ ${0}$ ${6}$ ${1}$ Together, the babies weigh 16.03 pounds.